The Soviet Union or Union of Soviet Socialist Republics was born and expanded as a union of Soviet republics formed within the territory of the Russian Empire abolished by the Russian Revolution of 1917 followed by the Russian Civil War of 1918-1920. The geographic boundaries of the Soviet Union varied with time, but after the last major territorial annexations of the Baltic States, eastern Poland, Bessarabia, and certain other territories during World War II, from 1945 until dissolution the boundaries approximately corresponded to those of late Imperial Russia, with the notable exclusions of Poland and Finland. Established by four Soviet Socialist Republics, the USSR grew to contain 15 constituent or union republics by 1956: Armenian SSR, Azerbaijan SSR, Byelorussian SSR, Estonian SSR, Georgian SSR, Kazakh SSR, Kyrgyz SSR, Latvian SSR, Lithuanian SSR, Moldavian SSR, Russian SFSR, Tajik SSR, Turkmen SSR, Ukrainian SSR, and Uzbek SSR.[1] The republics were part of a highly centralized federal union that was dominated by the Russian SFSR. After the USSR's collapse in 1991, all 15 SSRs became independent countries. The Soviet Union was dissolved in 1991.

Notes and references

General remarks:

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Every entry has an introduction section in English. If other languages are native and/or official in an entity, introductions in other languages are added in separate sections. The text of the introduction(s) is based on the content of the Wikipedia encyclopedia. For sources of the introduction see therefore the Wikipedia entries linked to. The same goes for the texts in the history sections.

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↑Romanization of Russian according to the BGN/PCGN standard: Soyuz Sovetskikh Sotsialisticheskikh Respublik, (SSSR, Sovetskiy Soyuz. Another used romanization is the ISO 9 standard.

↑Romanization of Russian according to the BGN/PCGN standard: Moskva. Another used romanization is the ISO 9 standard.

↑The text of the summary of the history is mainly based on the text in Wikipedia.